Implications of a new 17 Mev vector boson on Higgs, SUSY

[kodama]

You listed some publications that have a few keywords in common with your previous post. That is not a publication suggesting what you asked about.

what i am asking is whether this hypothetical 16.7 mev boson described by Feng could be harmonized with the new force described by composite higgs theories. LHC did not find any evidence of natural SUSY so perhaps the higgs is a composite entity

 

[kodama]

Re-visit all threads from 2011. Or every other year in the past 50 years. How many new interactions have been found? Do you see a pattern?

what is your opinion of extensions of the SM involving W' and Z' extra copy of SU(2) or U(1) gauge group as part of the little Higgs models, ultimate purpose is to explain higgs stability without supersymmetry?
do you think it is well motivated and plausible?

i ask b/c another alternative explanation is that 16.7 mev is a Z' boson and not a protophobic boson.

The 17 MeV Anomaly in Beryllium Decays and U(1) Portal to Dark Matter
Chian-Shu Chen, Guey-Lin Lin, Yen-Hsun Lin, Fanrong Xu
(Submitted on 23 Sep 2016)
The experiment of Krasznahorkay \textit{et al} observed the transition of a 8Be excited state to its ground state and accompanied by an emission of e+e− pair with 17 MeV invariant mass. This 6.8σ anomaly can be fitted by a new light gauge boson. We consider the new particle as a U(1) gauge boson, Z′, which plays as a portal linking dark sector and visible sector. In particular, we study the new U(1) gauge symmetry as a hidden or non-hidden group separately. The generic hidden U(1) model, referred to as dark Z model, is excluded by imposing various experimental constraints. On the other hand, a non-hidden Z′ is allowed due to additional interactions between Z′ and Standard Model fermions. We also study the implication of the dark matter direct search on such a scenario. We found the search for the DM-nucleon scattering excludes the range of DM mass above 500 MeV. However, the DM-electron scattering for MeV-scale DM is still allowed by current constraints for non-hidden U(1) models. It is possible to test the underlying U(1) portal model by the future Si and Ge detectors with 5e− threshold charges.
Comments: 13 pages, 3 figures
Subjects: High Energy Physics - Phenomenology (hep-ph)
Cite as: arXiv:1609.07198 [hep-ph]

these papers also try to connect anomaly with dark matter so there's that.

another explanation is a light axion like pseudoscalar

Possible Explanation of the Electron Positron Anomaly at 17 MeV in 8Be Transitions Through a Light Pseudoscalar
Ulrich Ellwanger, Stefano Moretti
(Submitted on 6 Sep 2016)
We estimate the values of Yukawa couplings of a light pseudoscalar A with a mass of about 17 MeV, which would explain the 8Be anomaly observed in the Atomki pair spectrometer experiment. The resulting couplings of A to up and down type quarks are about 0.3 times the coupling of the standard Higgs boson. Then constraints from K and B decays require that loop contributions to flavour changing vertices cancel at least at the 10% level. Constraints from beam dump experiments require the coupling of A to electrons to be larger than about 4 times the coupling of the standard Higgs boson, leading to a short enough A life time consistent with an explanation of the anomaly.
Comments: 12 pages, no figures
Subjects: High Energy Physics - Phenomenology (hep-ph)
Report number: LPT Orsay 16-54
Cite as: arXiv:1609.01669 [hep-ph]

reminds me of the 500+ papers on the 750 gev diphoton bump

the 16.7 mev bump could be a protophobic gauge boson mediating a new force, but it could also be evidence of Z' boson present in little higgs and a axion like pseudoscalar

these 3 explanations also offer possible explanations with dark matter.

presumably an ep collider would offer different results for these various explanations.

 

[ohwilleke]

The overwhelmingly more likely possibility is that 8Be decays can be explained without BSM physics of any kind. First principles models of atomic nuclei that are even moderately complex, like 8Be,just don't exist. It is far more likely that there is some error in the predicted value due to failure to consider some SM factor that is present in 8Be than it is that BSM physics are present. The poor track record of the investigators suggesting the alternatives makes that particularly likely to be the case.

 

[kodama]

The overwhelmingly more likely possibility is that 8Be decays can be explained without BSM physics of any kind. First principles models of atomic nuclei that are even moderately complex, like 8Be,just don't exist. It is far more likely that there is some error in the predicted value due to failure to consider some SM factor that is present in 8Be than it is that BSM physics are present. The poor track record of the investigators suggesting the alternatives makes that particularly likely to be the case.

true enough. not really all that different from the 750 diphoton bump lhc saw.

do u have an opinion on little higgs and w' z' bosons - independent of this?

 

[ohwilleke]

Little Higgs does not look promising as we should start seeing phenomenological effects of it by now, and we don't. https://arxiv.org/pdf/hep-ph/0502182v1.pdf

Per PDG the W' exclusion is 3.2 TeV (about 40 times the W boson mass) and the Z' exclusion is 2.9 TeV (about 37 times the Z boson mass)
http://pdglive.lbl.gov/Particle.action?node=S056 (subject in each case to assumptions about their properties). Equally important, we don't have a compelling need for either a W' or a Z' to explain anything. The SM is complete and healthy mathematically to 10^15 GeV+